Below is a picture of an electromagnet made by wrapping a wire around an iron nail and connecting it to a battery. The electromagnet can be turned off by disconnecting it from the battery. A teacher helps students perform 2 experiments to test the variables that affect the electromagnet’s magnetic strength.%C2%A0 %C2%A0 Experiment 1 The students build an electromagnet using a 4.5 volt battery connected to an iron nail with coils wrapped around it. They change the number of coils around the nail and record how many paperclips the electromagnet can pick up each time. The results are shown in the table below. Experiment 2 In the second experiment, the students keep the same number of coils around the nail and records how many paperclips the electromagnet can pick up using different batteries. %C2%A0 Which question can be answered based on the results of Experiment 2?

Which variable affects the electromagnet's magnetic strength?